High Rejection Rates with Low Dose Immunosuppression in Old for Old Kidney Transplantation

Background: The aim of our one year prospective multicenter randomized controlled trial was to compare the effects of low dose tacrolimus (LD-Tac) and mycophenolate-mofetil (MMF) in elderly kidney transplant recipients (KTR) within the Eurotransplant Senior Program (ESP). Methods: Ninety kidney transplant recipients (KTR) were enrolled. All received baseline immunosuppression (IS) with daclizumab induction (2mg/kg), LD-Tac (trough level 5-8ng/ml), MMF (2g/d) and steroids. After three months, patients were randomized to receive either MMF (1-2g/d) and steroids or LD-Tac and steroids. Results: Of the 90 KTR enrolled, 38 patients (P) dropped out prior to randomization due to severe rejection (5P), intolerance of MMF dose (3P), out of target Tac level (3P), or other protocol violations (27P). Prior to randomization, delayed graft function occurred in 41%, and acute rejections in 58% of the KTR. Creatinine clearance in the MMF group was superior compared to the LD-Tac group after 6 months (p<0.05) and 12 months (p<0.05), whereas rejection and infection rates were not different. Conclusion: Unfortunately, the high dropout rate led to underpowerment of the study. However, the high incidence of early rejection demonstrates that low dose IS in this phase after transplantation is not sufficient for older patients. (ClinicalTrials.gov Identifier: NCT00912678).